Future proof test_util:fake_pid/1

in OTP 23 pids hava new type tag: 88 (previously 103). To account for
this copy whatever the local pid returns and insert that in the output
binary.

Author: kjnilsson

test/test_util.erl

@@ -10,8 +10,19 @@ fake_pid(Node) ->
     ThisNodeSize = size(term_to_binary(node())) + 1,
     Pid = spawn(fun () -> ok end),
     %% drop the local node data from a local pid
-    <<_:ThisNodeSize/binary, LocalPidData/binary>> = term_to_binary(Pid),
+    <<Pre:ThisNodeSize/binary, LocalPidData/binary>> = term_to_binary(Pid),
     S = size(NodeBin),
+    %% get the encoding type of the pid
+    <<_:8, Type:8/unsigned, _/binary>> = Pre,
     %% replace it with the incoming node binary
-    Final = <<131,103, 100, S:16/unsigned, NodeBin/binary, LocalPidData/binary>>,
+    Final = <<131, Type, 100, S:16/unsigned, NodeBin/binary, LocalPidData/binary>>,
     binary_to_term(Final).
+
+-ifdef(TEST).
+-include_lib("eunit/include/eunit.hrl").
+
+fake_pid_test() ->
+    _ = fake_pid(banana),
+    ok.
+
+-endif.